if you give only default table space it means whenever the object's are created by this user will be created in that default tablespace.quota must be provided on that tablespace to create objects.quota is the size provided to user to create objects in limits on size. this is helpful when 50 or 100 users have same tablespace and you give 100 MB to everyone so that no other user can create object more them 100MB and spzce is also available for other users.

Niket Kumar wrote:
if you give only default table space it means whenever the object's are created by this user will be created in that default tablespace.quota must be provided on that tablespace to create objects.quota is the size provided to user to create objects in limits on size. this is helpful when 50 or 100 users have same tablespace and you give 100 MB to everyone so that no other user can create object more them 100MB and spzce is also available for other users.

there is no need to grant quota on a tablespace if the user already has RESOURCE, which is one reason why you should never grant RESOURCE to anyone. Clearly, there is sonething else going on in your database. Another indication that things are not as they seem is that in 11.2.x by default you do not need quota on a tablespace (or unlimnited tablespace) to create tables, because by default segment creation is deferred. So you get the error only when you try to insert into the table:

there is no need to grant quota on a tablespace if the user already has RESOURCE, which is one reason why you should never grant RESOURCE to anyone. Clearly, there is sonething else going on in your database. Another indication that things are not as they seem is that in 11.2.x by default you do not need quota on a tablespace (or unlimnited tablespace) to create tables, because by default segment creation is deferred. So you get the error only when you try to insert into the table: